From 333c3f18c06fb4a380646add8a90ef5fda092132 Mon Sep 17 00:00:00 2001 From: christiaans Date: Fri, 7 Jul 2006 09:49:31 +0000 Subject: [PATCH] Initial commit. Expirimental code, please note this is not yet fully functional. --- src/core/snmp/asn1_dec.c | 614 ++++++++++++++++++++++++++++ src/core/snmp/asn1_enc.c | 583 ++++++++++++++++++++++++++ src/core/snmp/mib2.c | 593 +++++++++++++++++++++++++++ src/core/snmp/msg_in.c | 771 +++++++++++++++++++++++++++++++++++ src/core/snmp/msg_out.c | 622 ++++++++++++++++++++++++++++ src/include/lwip/snmp_asn1.h | 90 ++++ src/include/lwip/snmp_msg.h | 267 ++++++++++++ 7 files changed, 3540 insertions(+) create mode 100644 src/core/snmp/asn1_dec.c create mode 100644 src/core/snmp/asn1_enc.c create mode 100644 src/core/snmp/mib2.c create mode 100644 src/core/snmp/msg_in.c create mode 100644 src/core/snmp/msg_out.c create mode 100644 src/include/lwip/snmp_asn1.h create mode 100644 src/include/lwip/snmp_msg.h diff --git a/src/core/snmp/asn1_dec.c b/src/core/snmp/asn1_dec.c new file mode 100644 index 00000000..064775c5 --- /dev/null +++ b/src/core/snmp/asn1_dec.c @@ -0,0 +1,614 @@ +/** + * @file + * [EXPIRIMENTAL] Abstract Syntax Notation One (ISO 8824, 8825) decoding + * + * @todo not optimised (yet), favor correctness over speed, favor speed over size + */ + +/* + * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Christiaan Simons + */ + +#include "lwip/opt.h" +#include "lwip/snmp_asn1.h" + +#if LWIP_SNMP +/** + * Retrieves type field from incoming pbuf chain. + * + * @param p points to a pbuf holding an ASN1 coded type field + * @param ofs points to the offset within the pbuf chain of the ASN1 coded type field + * @param type return ASN1 type + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode + */ +err_t +snmp_asn1_dec_type(struct pbuf *p, u16_t ofs, u8_t *type) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + *type = *msg_ptr; + return ERR_OK; + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Decodes length field from incoming pbuf chain into host length. + * + * @param p points to a pbuf holding an ASN1 coded length + * @param ofs points to the offset within the pbuf chain of the ASN1 coded length + * @param octets_used returns number of octets used by the length code + * @param length return host order length, upto 64k + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode + */ +err_t +snmp_asn1_dec_length(struct pbuf *p, u16_t ofs, u8_t *octets_used, u16_t *length) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + + if (*msg_ptr < 0x80) + { + /* primitive definite length format */ + *octets_used = 1; + *length = *msg_ptr; + return ERR_OK; + } + else if (*msg_ptr == 0x80) + { + /* constructed indefinite length format, termination with two zero octets */ + u8_t zeros; + u8_t i; + + *length = 0; + zeros = 0; + while (zeros != 2) + { + i = 2; + while (i > 0) + { + i--; + (*length) += 1; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + if (*msg_ptr == 0) + { + zeros++; + if (zeros == 2) + { + /* stop while (i > 0) */ + i = 0; + } + } + else + { + zeros = 0; + } + } + } + *octets_used = 1; + return ERR_OK; + } + else if (*msg_ptr == 0x81) + { + /* constructed definite length format, one octet */ + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + *length = *msg_ptr; + *octets_used = 2; + return ERR_OK; + } + else if (*msg_ptr == 0x82) + { + u8_t i; + + /* constructed definite length format, two octets */ + i = 2; + while (i > 0) + { + i--; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + if (i == 0) + { + /* least significant length octet */ + *length |= *msg_ptr; + } + else + { + /* most significant length octet */ + *length = (*msg_ptr) << 8; + } + } + *octets_used = 3; + return ERR_OK; + } + else + { + /* constructed definite length format 3..127 octets, this is too big (>64k) */ + /** @todo: do we need to accept inefficient codings with many leading zero's? */ + *octets_used = 1 + ((*msg_ptr) & 0x7f); + return ERR_ARG; + } + } + p = p->next; + } + + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Decodes positive integer (counter, gauge, timeticks) into u32_t. + * + * @param p points to a pbuf holding an ASN1 coded integer + * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer + * @param len length of the coded integer field + * @param value return host order integer + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode + * + * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded + * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value + * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!! + */ +err_t +snmp_asn1_dec_u32t(struct pbuf *p, u16_t ofs, u16_t len, u32_t *value) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + if ((len > 0) && (len < 6)) + { + /* start from zero */ + *value = 0; + if (*msg_ptr & 0x80) + { + /* negative, expecting zero sign bit! */ + return ERR_ARG; + } + else + { + /* positive */ + if ((len > 1) && (*msg_ptr == 0)) + { + /* skip leading "sign byte" octet 0x00 */ + len--; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + } + /* OR octets with value */ + while (len > 1) + { + len--; + *value |= *msg_ptr; + *value <<= 8; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + *value |= *msg_ptr; + return ERR_OK; + } + else + { + return ERR_ARG; + } + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Decodes integer into s32_t. + * + * @param p points to a pbuf holding an ASN1 coded integer + * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer + * @param len length of the coded integer field + * @param value return host order integer + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode + * + * @note ASN coded integers are _always_ signed! + */ +err_t +snmp_asn1_dec_s32t(struct pbuf *p, u16_t ofs, u16_t len, s32_t *value) +{ + u16_t plen, base; + u8_t *msg_ptr; + u8_t sign; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + if ((len > 0) && (len < 5)) + { + if (*msg_ptr & 0x80) + { + /* negative, start from -1 */ + *value = -1; + sign = 1; + } + else + { + /* positive, start from 0 */ + *value = 0; + sign = 0; + } + /* OR/AND octets with value */ + while (len > 1) + { + len--; + if (sign) + { + *value &= *msg_ptr; + } + else + { + *value |= *msg_ptr; + } + *value <<= 8; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + if (sign) + { + *value &= *msg_ptr; + } + else + { + *value |= *msg_ptr; + } + return ERR_OK; + } + else + { + return ERR_ARG; + } + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Decodes object identifier from incoming message into array of s32_t. + * + * @param p points to a pbuf holding an ASN1 coded object identifier + * @param ofs points to the offset within the pbuf chain of the ASN1 coded object identifier + * @param len length of the coded object identifier + * @param oid return object identifier struct + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode + */ +err_t +snmp_asn1_dec_oid(struct pbuf *p, u16_t ofs, u16_t len, struct snmp_obj_id *oid) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + + if ((len > 1) && (*msg_ptr == 0x2B)) + { + s32_t *oid_ptr; + + /* we have compressed 1.3 (iso.org) Z = (X * 40) + Y */ + len--; + /* proceed to .dod */ + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + oid->len = 0; + oid_ptr = &oid->id[0]; + while ((len > 0) && (oid->len < LWIP_SNMP_OBJ_ID_LEN)) + { + /* sub-identifier uses multiple octets */ + if (*msg_ptr & 0x80) + { + s32_t sub_id = 0; + + while ((*msg_ptr & 0x80) && (len > 1)) + { + len--; + sub_id = (sub_id << 7) + (*msg_ptr & ~0x80); + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + if (!(*msg_ptr & 0x80) && (len > 0)) + { + /* last octet sub-identifier */ + len--; + sub_id = (sub_id << 7) + *msg_ptr; + *oid_ptr = sub_id; + } + } + else + { + /* !(*msg_ptr & 0x80) sub-identifier uses single octet */ + len--; + *oid_ptr = *msg_ptr; + } + if (len > 0) + { + /* remaining oid bytes available ... */ + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + oid_ptr++; + oid->len++; + } + if (len == 0) + { + /* len == 0, end of oid */ + return ERR_OK; + } + else + { + /* len > 0, oid->len == LWIP_SNMP_OBJ_ID_LEN or malformed encoding */ + return ERR_ARG; + } + } + else + { + /* length <= 1 OR prefix not 1.3 (iso.org) */ + return ERR_ARG; + } + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Decodes (copies) raw data (ip-addresses, octet strings, opaque encoding) + * from incoming message into array. + * + * @param p points to a pbuf holding an ASN1 coded raw data + * @param ofs points to the offset within the pbuf chain of the ASN1 coded raw data + * @param len length of the coded raw data (zero is valid, e.g. empty string!) + * @param raw_len length of the raw return value + * @param raw return raw bytes + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode + */ +err_t +snmp_asn1_dec_raw(struct pbuf *p, u16_t ofs, u16_t len, u16_t raw_len, u8_t *raw) +{ + u16_t plen, base; + u8_t *msg_ptr; + + if (len > 0) + { + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + if (raw_len >= len) + { + while (len > 1) + { + /* copy len - 1 octets */ + len--; + *raw = *msg_ptr; + raw++; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + /* copy last octet */ + *raw = *msg_ptr; + return ERR_OK; + } + else + { + /* raw_len < len, not enough dst space */ + return ERR_ARG; + } + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; + } + else + { + /* len == 0, empty string */ + return ERR_OK; + } +} + +#endif /* LWIP_SNMP */ \ No newline at end of file diff --git a/src/core/snmp/asn1_enc.c b/src/core/snmp/asn1_enc.c new file mode 100644 index 00000000..279f7c1f --- /dev/null +++ b/src/core/snmp/asn1_enc.c @@ -0,0 +1,583 @@ +/** + * @file + * [EXPIRIMENTAL] Abstract Syntax Notation One (ISO 8824, 8825) encoding + * + * @todo not optimised (yet), favor correctness over speed, favor speed over size + */ + +/* + * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Christiaan Simons + */ + +#include "lwip/opt.h" +#include "lwip/snmp_asn1.h" + +#if LWIP_SNMP +/** + * Returns octet count for length. + * + * @param length + * @param octets_needed points to the return value + */ +void +snmp_asn1_enc_length_cnt(u16_t length, u8_t *octets_needed) +{ + if (length < 0x80U) + { + *octets_needed = 1; + } + else if (length < 0x100U) + { + *octets_needed = 2; + } + else + { + *octets_needed = 3; + } +} + +/** + * Returns octet count for an u32_t. + * + * @param value + * @param octets_needed points to the return value + * + * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded + * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value + * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!! + */ +void +snmp_asn1_enc_u32t_cnt(u32_t value, u16_t *octets_needed) +{ + if (value < 0x80UL) + { + *octets_needed = 1; + } + else if (value < 0x8000UL) + { + *octets_needed = 2; + } + else if (value < 0x800000UL) + { + *octets_needed = 3; + } + else if (value < 0x80000000UL) + { + *octets_needed = 4; + } + else + { + *octets_needed = 5; + } +} + +/** + * Returns octet count for an s32_t. + * + * @param value + * @param octets_needed points to the return value + * + * @note ASN coded integers are _always_ signed. + */ +void +snmp_asn1_enc_s32t_cnt(s32_t value, u16_t *octets_needed) +{ + if (value < 0) + { + value = ~value; + } + if (value < 0x80L) + { + *octets_needed = 1; + } + else if (value < 0x8000L) + { + *octets_needed = 2; + } + else if (value < 0x800000L) + { + *octets_needed = 3; + } + else + { + *octets_needed = 4; + } +} + +/** + * Returns octet count for an object identifier. + * + * @param ident_len object identifier array length + * @param ident points to object identifier array + * @param octets_needed points to the return value + */ +void +snmp_asn1_enc_oid_cnt(u8_t ident_len, s32_t *ident, u16_t *octets_needed) +{ + s32_t sub_id; + u8_t cnt; + + cnt = 0; + while(ident_len > 0) + { + ident_len--; + sub_id = *ident; + + sub_id >>= 7; + cnt++; + while(sub_id > 0) + { + sub_id >>= 7; + cnt++; + } + ident++; + } + /* one extra for compressed iso.dod. prefix */ + cnt++; + *octets_needed = cnt; +} + +/** + * Encodes ASN type field into a pbuf chained ASN1 msg. + * + * @param p points to output pbuf to encode value into + * @param ofs points to the offset within the pbuf chain + * @param type input ASN1 type + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode + */ +err_t +snmp_asn1_enc_type(struct pbuf *p, u16_t ofs, u8_t type) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + *msg_ptr = type; + return ERR_OK; + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Encodes host order length field into a pbuf chained ASN1 msg. + * + * @param p points to output pbuf to encode length into + * @param ofs points to the offset within the pbuf chain + * @param length is the host order length to be encoded + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode + * + * @todo also add octets_used instead of compares?? + * @todo encode "type" in this function as well?? + */ +err_t +snmp_asn1_enc_length(struct pbuf *p, u16_t ofs, u16_t length) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + + if (length < 0x80) + { + *msg_ptr = length; + return ERR_OK; + } + else if (length < 0x100) + { + *msg_ptr = 0x81; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + *msg_ptr = length; + return ERR_OK; + } + else + { + u8_t i; + + /* length >= 0x100 && length <= 0xFFFF */ + *msg_ptr = 0x82; + i = 2; + while (i > 0) + { + i--; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + if (i == 0) + { + /* least significant length octet */ + *msg_ptr = length; + } + else + { + /* most significant length octet */ + *msg_ptr = length >> 8; + } + } + return ERR_OK; + } + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Encodes u32_t (counter, gauge, timeticks) into a pbuf chained ASN1 msg. + * + * @param p points to output pbuf to encode value into + * @param ofs points to the offset within the pbuf chain + * @param octets_needed encoding length (from snmp_asn1_enc_u32t_cnt()) + * @param value is the host order u32_t value to be encoded + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode + * + * @see snmp_asn1_enc_u32t_cnt() + */ +err_t +snmp_asn1_enc_u32t(struct pbuf *p, u16_t ofs, u8_t octets_needed, u32_t value) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + + if (octets_needed == 5) + { + /* not enough bits in 'value' add leading 0x00 */ + octets_needed--; + *msg_ptr = 0x00; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + while (octets_needed > 1) + { + octets_needed--; + *msg_ptr = value >> (octets_needed << 3); + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + /* (only) one least significant octet */ + *msg_ptr = value; + return ERR_OK; + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Encodes s32_t integer into a pbuf chained ASN1 msg. + * + * @param p points to output pbuf to encode value into + * @param ofs points to the offset within the pbuf chain + * @param octets_needed encoding length (from snmp_asn1_enc_s32t_cnt()) + * @param value is the host order s32_t value to be encoded + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode + * + * @see snmp_asn1_enc_s32t_cnt() + */ +err_t +snmp_asn1_enc_s32t(struct pbuf *p, u16_t ofs, u8_t octets_needed, s32_t value) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + + while (octets_needed > 1) + { + octets_needed--; + *msg_ptr = value >> (octets_needed << 3); + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + /* (only) one least significant octet */ + *msg_ptr = value; + return ERR_OK; + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Encodes object identifier into a pbuf chained ASN1 msg. + * + * @param p points to output pbuf to encode oid into + * @param ofs points to the offset within the pbuf chain + * @param ident_len object identifier array length + * @param ident points to object identifier array + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode + */ +err_t +snmp_asn1_enc_oid(struct pbuf *p, u16_t ofs, u8_t ident_len, s32_t *ident) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + /* add compressed prefix .iso.dod */ + *msg_ptr = 0x2b; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + while (ident_len > 0) + { + s32_t sub_id; + u8_t shift; + + ident_len--; + sub_id = *ident; + + shift = 28; + while(shift > 0) + { + u8_t code; + + code = sub_id >> shift; + if (code != 0) + { + *msg_ptr = code | 0x80; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + shift -= 7; + } + *msg_ptr = (u8_t)sub_id & 0x7F; + if (ident_len > 0) + { + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + /* proceed to next sub-identifier */ + ident++; + } + return ERR_OK; + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +/** + * Encodes raw data (octet string, opaque) into a pbuf chained ASN1 msg. + * + * @param p points to output pbuf to encode raw data into + * @param ofs points to the offset within the pbuf chain + * @param raw_len raw data length + * @param raw points raw data + * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode + */ +err_t +snmp_asn1_enc_raw(struct pbuf *p, u16_t ofs, u8_t raw_len, u8_t *raw) +{ + u16_t plen, base; + u8_t *msg_ptr; + + plen = 0; + while (p != NULL) + { + base = plen; + plen += p->len; + if (ofs < plen) + { + msg_ptr = p->payload; + msg_ptr += ofs - base; + + while (raw_len > 1) + { + /* copy raw_len - 1 octets */ + raw_len--; + *msg_ptr = *raw; + raw++; + ofs += 1; + if (ofs >= plen) + { + /* next octet in next pbuf */ + p = p->next; + if (p == NULL) { return ERR_ARG; } + msg_ptr = p->payload; + plen += p->len; + } + else + { + /* next octet in same pbuf */ + msg_ptr++; + } + } + /* copy last octet */ + *msg_ptr = *raw; + return ERR_OK; + } + p = p->next; + } + /* p == NULL, ofs >= plen */ + return ERR_ARG; +} + +#endif /* LWIP_SNMP */ diff --git a/src/core/snmp/mib2.c b/src/core/snmp/mib2.c new file mode 100644 index 00000000..b4888466 --- /dev/null +++ b/src/core/snmp/mib2.c @@ -0,0 +1,593 @@ +/** + * @file + * [EXPIRIMENTAL] Management Information Base II (RFC1213) objects and functions + */ + +/* + * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Christiaan Simons + */ + +#include "arch/cc.h" +#include "lwip/opt.h" +#include "lwip/snmp.h" +#include "lwip/snmp_asn1.h" +/* #include "lwip/snmp_structs.h" */ + +#if LWIP_SNMP + +#ifndef SNMP_ENTERPRISE_ID +/** + * IANA assigned enterprise ID for lwIP is 26381 + * @see http://www.iana.org/assignments/enterprise-numbers + * @note this enterprise ID is assigned to the lwIP project, + * all object identifiers living under this ID are assigned + * by the lwIP maintainers (contact Christiaan Simons)! + * + * If you need to create your own private MIB you'll need + * to apply for your own enterprise ID with IANA: + * http://www.iana.org/numbers.html + */ +#define SNMP_ENTERPRISE_ID 26381 +#endif +#ifndef SNMP_SYSOBJID_LEN +#define SNMP_SYSOBJID_LEN 5 +#endif +#ifndef SNMP_SYSOBJID +#define SNMP_SYSOBJID {6, 1, 4, 1, SNMP_ENTERPRISE_ID} +#endif + +/** @todo MIB-tree will be inserted here */ + +/** .iso.org.dod.internet.mgmt.mib-2.sysObjectID */ +const struct snmp_obj_id sysobjid = {SNMP_SYSOBJID_LEN, SNMP_SYSOBJID}; +/** enterprise ID for generic TRAPs, .iso.org.dod.internet.mgmt.mib-2.snmp */ +const struct snmp_obj_id snmpgrp_id = {5,{6,1,2,1,11}}; + +/* mib-2.system counter(s) */ +static u32_t sysuptime; +/* mib-2.interfaces counter(s) */ +static u32_t ifinoctets, + ifinucastpkts, + ifinnucastpkts, + ifindiscards, + ifoutoctets, + ifoutucastpkts, + ifoutnucastpkts, + ifoutdiscards; +/* mib-2.ip counter(s) */ +static u32_t ipindelivers, + ipinreceives, + ipindiscards, + ipoutdiscards, + ipoutrequests, + ipunknownprotos; +/* mib-2.icmp counter(s) */ +static u32_t icmpinmsgs, + icmpinerrors, + icmpindestunreachs, + icmpintimeexcds, + icmpinparmprobs, + icmpinsrcquenchs, + icmpinredirects, + icmpinechos, + icmpinechoreps, + icmpintimestamps, + icmpintimestampreps, + icmpinaddrmasks, + icmpinaddrmaskreps, + icmpoutmsgs, + icmpouterrors, + icmpoutdestunreachs, + icmpouttimeexcds, + icmpoutparmprobs, + icmpoutsrcquenchs, + icmpoutredirects, + icmpoutechos, + icmpoutechoreps, + icmpouttimestamps, + icmpouttimestampreps, + icmpoutaddrmasks, + icmpoutaddrmaskreps; +/* mib-2.tcp counter(s) */ +static u32_t tcpactiveopens, + tcppassiveopens, + tcpattemptfails, + tcpestabresets, + tcpcurrestab, + tcpinsegs, + tcpoutsegs, + tcpretranssegs, + tcpinerrs, + tcpoutrsts; +/* mib-2.udp counter(s) */ +static u32_t udpindatagrams, + udpnoports, + udpinerrors, + udpoutdatagrams; +/* mib-2.snmp counter(s) */ +static u32_t snmpinpkts, + snmpoutpkts, + snmpinbadversions, + snmpinbadcommunitynames, + snmpinbadcommunityuses, + snmpinasnparseerrs, + snmpintoobigs, + snmpinnosuchnames, + snmpinbadvalues, + snmpinreadonlys, + snmpingenerrs, + snmpintotalreqvars, + snmpintotalsetvars, + snmpingetrequests, + snmpingetnexts, + snmpinsetrequests, + snmpingetresponses, + snmpintraps, + snmpouttoobigs, + snmpoutnosuchnames, + snmpoutbadvalues, + snmpoutgenerrs, + snmpoutgetrequests, + snmpoutgetnexts, + snmpoutsetrequests, + snmpoutgetresponses, + snmpouttraps; + +/* prototypes of the following functions are in lwip/src/include/lwip/snmp.h */ + +/** + * Must be called at regular 10 msec interval from a timer interrupt + * or signal handler depending on your runtime environment. + */ +void snmp_inc_sysuptime(void) +{ + sysuptime++; +} + +void snmp_get_sysuptime(u32_t *value) +{ + *value = sysuptime; +} + +void snmp_get_sysobjid(const struct snmp_obj_id **oid) +{ + *oid = &sysobjid; +} + +void snmp_add_ifinoctets(u32_t value) +{ + ifinoctets += value; +} + +void snmp_inc_ifinucastpkts(void) +{ + ifinucastpkts++; +} + +void snmp_inc_ifinnucastpkts(void) +{ + ifinnucastpkts++; +} + +void snmp_inc_ifindiscards(void) +{ + ifindiscards++; +} + +void snmp_add_ifoutoctets(u32_t value) +{ + ifoutoctets += value; +} + +void snmp_inc_ifoutucastpkts(void) +{ + ifoutucastpkts++; +} + +void snmp_inc_ifoutnucastpkts(void) +{ + ifoutnucastpkts++; +} + +void snmp_inc_ifoutdiscards(void) +{ + ifoutdiscards++; +} + +void snmp_inc_ipindelivers(void) +{ + ipindelivers++; +} + +void snmp_inc_ipinreceives(void) +{ + ipinreceives++; +} + +void snmp_inc_ipindiscards(void) +{ + ipindiscards++; +} + +void snmp_inc_ipoutdiscards(void) +{ + ipoutdiscards++; +} + +void snmp_inc_ipoutrequests(void) +{ + ipoutrequests++; +} + +void snmp_inc_ipunknownprotos(void) +{ + ipunknownprotos++; +} + + +void snmp_inc_icmpinmsgs(void) +{ + icmpinmsgs++; +} + +void snmp_inc_icmpinerrors(void) +{ + icmpinerrors++; +} + +void snmp_inc_icmpindestunreachs(void) +{ + icmpindestunreachs++; +} + +void snmp_inc_icmpintimeexcds(void) +{ + icmpintimeexcds++; +} + +void snmp_inc_icmpinparmprobs(void) +{ + icmpinparmprobs++; +} + +void snmp_inc_icmpinsrcquenchs(void) +{ + icmpinsrcquenchs++; +} + +void snmp_inc_icmpinredirects(void) +{ + icmpinredirects++; +} + +void snmp_inc_icmpinechos(void) +{ + icmpinechos++; +} + +void snmp_inc_icmpinechoreps(void) +{ + icmpinechoreps++; +} + +void snmp_inc_icmpintimestamps(void) +{ + icmpintimestamps++; +} + +void snmp_inc_icmpintimestampreps(void) +{ + icmpintimestampreps++; +} + +void snmp_inc_icmpinaddrmasks(void) +{ + icmpinaddrmasks++; +} + +void snmp_inc_icmpinaddrmaskreps(void) +{ + icmpinaddrmaskreps++; +} + +void snmp_inc_icmpoutmsgs(void) +{ + icmpoutmsgs++; +} + +void snmp_inc_icmpouterrors(void) +{ + icmpouterrors++; +} + +void snmp_inc_icmpoutdestunreachs(void) +{ + icmpoutdestunreachs++; +} + +void snmp_inc_icmpouttimeexcds(void) +{ + icmpouttimeexcds++; +} + +void snmp_inc_icmpoutparmprobs(void) +{ + icmpoutparmprobs++; +} + +void snmp_inc_icmpoutsrcquenchs(void) +{ + icmpoutsrcquenchs++; +} + +void snmp_inc_icmpoutredirects(void) +{ + icmpoutredirects++; +} + +void snmp_inc_icmpoutechos(void) +{ + icmpoutechos++; +} + +void snmp_inc_icmpoutechoreps(void) +{ + icmpoutechoreps++; +} + +void snmp_inc_icmpouttimestamps(void) +{ + icmpouttimestamps++; +} + +void snmp_inc_icmpouttimestampreps(void) +{ + icmpouttimestampreps++; +} + +void snmp_inc_icmpoutaddrmasks(void) +{ + icmpoutaddrmasks++; +} + +void snmp_inc_icmpoutaddrmaskreps(void) +{ + icmpoutaddrmaskreps++; +} + +void snmp_inc_tcpactiveopens(void) +{ + tcpactiveopens++; +} + +void snmp_inc_tcppassiveopens(void) +{ + tcppassiveopens++; +} + +void snmp_inc_tcpattemptfails(void) +{ + tcpattemptfails++; +} + +void snmp_inc_tcpestabresets(void) +{ + tcpestabresets++; +} + +void snmp_inc_tcpcurrestab(void) +{ + tcpcurrestab++; +} + +void snmp_inc_tcpinsegs(void) +{ + tcpinsegs++; +} + +void snmp_inc_tcpoutsegs(void) +{ + tcpoutsegs++; +} + +void snmp_inc_tcpretranssegs(void) +{ + tcpretranssegs++; +} + +void snmp_inc_tcpinerrs(void) +{ + tcpinerrs++; +} + +void snmp_inc_tcpoutrsts(void) +{ + tcpoutrsts++; +} + +void snmp_inc_udpindatagrams(void) +{ + udpindatagrams++; +} + +void snmp_inc_udpnoports(void) +{ + udpnoports++; +} + +void snmp_inc_udpinerrors(void) +{ + udpinerrors++; +} + +void snmp_inc_udpoutdatagrams(void) +{ + udpoutdatagrams++; +} + +void snmp_inc_snmpinpkts(void) +{ + snmpinpkts++; +} + +void snmp_inc_snmpoutpkts(void) +{ + snmpoutpkts++; +} + +void snmp_inc_snmpinbadversions(void) +{ + snmpinbadversions++; +} + +void snmp_inc_snmpinbadcommunitynames(void) +{ + snmpinbadcommunitynames++; +} + +void snmp_inc_snmpinbadcommunityuses(void) +{ + snmpinbadcommunityuses++; +} + +void snmp_inc_snmpinasnparseerrs(void) +{ + snmpinasnparseerrs++; +} + +void snmp_inc_snmpintoobigs(void) +{ + snmpintoobigs++; +} + +void snmp_inc_snmpinnosuchnames(void) +{ + snmpinnosuchnames++; +} + +void snmp_inc_snmpinbadvalues(void) +{ + snmpinbadvalues++; +} + +void snmp_inc_snmpinreadonlys(void) +{ + snmpinreadonlys++; +} + +void snmp_inc_snmpingenerrs(void) +{ + snmpingenerrs++; +} + +void snmp_add_snmpintotalreqvars(u8_t value) +{ + snmpintotalreqvars += value; +} + +void snmp_add_snmpintotalsetvars(u8_t value) +{ + snmpintotalsetvars += value; +} + +void snmp_inc_snmpingetrequests(void) +{ + snmpingetrequests++; +} + +void snmp_inc_snmpingetnexts(void) +{ + snmpingetnexts++; +} + +void snmp_inc_snmpinsetrequests(void) +{ + snmpinsetrequests++; +} + +void snmp_inc_snmpingetresponses(void) +{ + snmpingetresponses++; +} + +void snmp_inc_snmpintraps(void) +{ + snmpintraps++; +} + +void snmp_inc_snmpouttoobigs(void) +{ + snmpouttoobigs++; +} + +void snmp_inc_snmpoutnosuchnames(void) +{ + snmpoutnosuchnames++; +} + +void snmp_inc_snmpoutbadvalues(void) +{ + snmpoutbadvalues++; +} + +void snmp_inc_snmpoutgenerrs(void) +{ + snmpoutgenerrs++; +} + +void snmp_inc_snmpoutgetrequests(void) +{ + snmpoutgetrequests++; +} + +void snmp_inc_snmpoutgetnexts(void) +{ + snmpoutgetnexts++; +} + +void snmp_inc_snmpoutsetrequests(void) +{ + snmpoutsetrequests++; +} + +void snmp_inc_snmpoutgetresponses(void) +{ + snmpoutgetresponses++; +} + +void snmp_inc_snmpouttraps(void) +{ + snmpouttraps++; +} + +void snmp_get_snmpgrpid(const struct snmp_obj_id **oid) +{ + *oid = &snmpgrp_id; +} + +#endif /* LWIP_SNMP */ \ No newline at end of file diff --git a/src/core/snmp/msg_in.c b/src/core/snmp/msg_in.c new file mode 100644 index 00000000..22d658ed --- /dev/null +++ b/src/core/snmp/msg_in.c @@ -0,0 +1,771 @@ +/** + * @file + * [EXPIRIMENTAL] SNMP input message processing (RFC1157). + * + * EXPIRIMENTAL dumb echo, this is not how the agent should respond. + * This is for test purposes only, DO NOT USE THIS CODE IN REAL WORLD!! + */ + +/* + * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Christiaan Simons + */ + +#include +#include "arch/cc.h" +#include "lwip/opt.h" +#include "lwip/ip_addr.h" +#include "lwip/mem.h" +#include "lwip/udp.h" +#include "lwip/stats.h" + +#include "lwip/snmp.h" +#include "lwip/snmp_asn1.h" +#include "lwip/snmp_msg.h" + + +#if LWIP_SNMP + +#define SNMP_CONCURRENT_REQUESTS 2 + +/* public (non-static) constants */ +/** SNMP v1 == 0 */ +const s32_t snmp_version = 0; +/** default SNMP community string */ +const char snmp_publiccommunity[7] = "public"; + +/* statically allocated buffers for SNMP_CONCURRENT_REQUESTS */ +struct snmp_msg_pstat msg_input_list[SNMP_CONCURRENT_REQUESTS]; +/* UDP Protocol Control Block */ +struct udp_pcb *snmp1_pcb = NULL; + +static void snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port); +static err_t snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat); +static err_t snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat); +static struct snmp_varbind* snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len); +static void snmp_varbind_free(struct snmp_varbind *vb); +static void snmp_varbind_list_free(struct snmp_varbind_root *root); +static void snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb); +static struct snmp_varbind* snmp_varbind_tail_remove(struct snmp_varbind_root *root); + + +void snmp_init(void) +{ + struct snmp_msg_pstat *msg_ps; + u8_t i; + + snmp1_pcb = udp_new(); + if (snmp1_pcb != NULL) + { + udp_recv(snmp1_pcb, snmp_recv, (void *)SNMP_IN_PORT); + udp_bind(snmp1_pcb, IP_ADDR_ANY, SNMP_IN_PORT); + } + msg_ps = &msg_input_list[0]; + for (i=0; istate = SNMP_MSG_EMPTY; + msg_ps->error_index = 0; + msg_ps->error_status = 0; + msg_ps++; + } + trap_msg.pcb = snmp1_pcb; +} + +/* lwIP UDP receive callback function */ +static void +snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port) +{ + struct udp_hdr *udphdr; + + /* suppress unused argument warning */ + if (arg); + /* peek in the UDP header (goto IP payload) */ + pbuf_header(p, UDP_HLEN); + udphdr = p->payload; + + /* check if datagram is really directed at us (including broadcast requests) */ + if ((pcb == snmp1_pcb) && (ntohs(udphdr->dest) == 161)) + { + struct snmp_msg_pstat *msg_ps; + u8_t i; + + /* traverse input message process list, look for SNMP_MSG_EMPTY */ + msg_ps = &msg_input_list[0]; + i = 0; + while ((istate != SNMP_MSG_EMPTY)) + { + i++; + msg_ps++; + } + if (i != SNMP_CONCURRENT_REQUESTS) + { + err_t err_ret; + u16_t payload_len; + u16_t payload_ofs; + u16_t varbind_ofs; + + /* accepting request */ + snmp_inc_snmpinpkts(); + /* register 'protocol control block' used */ + msg_ps->pcb = pcb; + /* source address (network order) */ + msg_ps->sip = *addr; + /* source port (host order (lwIP oddity)) */ + msg_ps->sp = port; + /* demultiplex variable bindings */ + msg_ps->state = SNMP_MSG_DEMUX; + /* read UDP payload length from UDP header */ + payload_len = ntohs(udphdr->len) - UDP_HLEN; + + /* adjust to UDP payload */ + payload_ofs = UDP_HLEN; + + /* check total length, version, community, pdu type */ + err_ret = snmp_pdu_header_check(p, payload_ofs, payload_len, &varbind_ofs, msg_ps); + if (err_ret == ERR_OK) + { + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv ok, community %s\n", msg_ps->community)); + + /* Builds a list of variable bindings. Copy the varbinds from the pbuf + chain to glue them when these are divided over two or more pbuf's. */ + err_ret = snmp_pdu_dec_varbindlist(p, varbind_ofs, &varbind_ofs, msg_ps); + if (err_ret == ERR_OK) + { + /* we've decoded the incoming message, release input msg now */ + pbuf_free(p); + + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv varbind cnt=%"U16_F"\n",(u16_t)msg_ps->invb.count)); + + /** @todo EXPIRIMENTAL dumb echo, this is not how the agent should respond. + This is for test purposes only, do not use this in real world!! */ + msg_ps->outvb = msg_ps->invb; + err_ret = snmp_send_response(msg_ps); + if (err_ret == ERR_MEM) + { + /* serious memory problem, can't return tooBig */ +#if LWIP_STATS + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv pbufs.used = %"U16_F"\n",lwip_stats.pbuf.used)); +#endif + } + else + { + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_response error_status = %"S32_F"\n",msg_ps->error_status)); + } + /* free varbinds (if available) */ + snmp_varbind_list_free(&msg_ps->invb); + msg_ps->state = SNMP_MSG_EMPTY; + } + else + { + /* varbind-list decode failed! */ + pbuf_free(p); + /** @todo should we return SNMP_ES_GENERROR here ? */ + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed")); + } + } + else + { + /* header check failed! */ + pbuf_free(p); + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_header_check() failed")); + } + } + else + { + /* exceeding number of concurrent requests */ + pbuf_free(p); + } + } + else + { + /* datagram not for us */ + pbuf_free(p); + } +} + +/** + * Checks and decodes incoming SNMP message header, logs header errors. + * + * @param p points to pbuf chain of SNMP message (UDP payload) + * @param ofs points to first octet of SNMP message + * @param pdu_len the length of the UDP payload + * @param ofs_ret returns the ofset of the variable bindings + * @param m_stat points to the current message request state return + * @return + * - ERR_OK SNMP header is sane and accepted + * - ERR_ARG SNMP header is either malformed or rejected + */ +static err_t +snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat) +{ + err_t derr; + u16_t len; + u8_t len_octets; + u8_t type; + s32_t version; + + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || + (pdu_len != (1 + len_octets + len)) || + (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) + { + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + if (type & SNMP_ASN1_CONSTR) + { + ofs += (1 + len_octets); + } + else + { + ofs += (1 + len_octets + len); + } + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) + { + /* can't decode or no integer (version) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &version); + if (derr != ERR_OK) + { + /* can't decode */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + if (version != 0) + { + /* not version 1 */ + snmp_inc_snmpinbadversions(); + return ERR_ARG; + } + if (type & SNMP_ASN1_CONSTR) + { + ofs += (1 + len_octets); + } + else + { + ofs += (1 + len_octets + len); + } + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR))) + { + /* can't decode or no octet string (community) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, SNMP_COMMUNITY_STR_LEN, m_stat->community); + if (derr != ERR_OK) + { + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + /* add zero terminator */ + len = ((len < (SNMP_COMMUNITY_STR_LEN))?(len):(SNMP_COMMUNITY_STR_LEN)); + m_stat->community[len] = 0; + m_stat->com_strlen = len; + if (strncmp(snmp_publiccommunity, m_stat->community, SNMP_COMMUNITY_STR_LEN) != 0) + { + /** @todo: move this if we need to check more names */ + snmp_inc_snmpinbadcommunitynames(); + + /** @todo: send authentication failure trap, if we have a trap destination */ + return ERR_ARG; + } + if (type & SNMP_ASN1_CONSTR) + { + ofs += (1 + len_octets); + } + else + { + ofs += (1 + len_octets + len); + } + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if (derr != ERR_OK) + { + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + switch(type) + { + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_REQ): + /* GetRequest PDU */ + snmp_inc_snmpingetrequests(); + derr = ERR_OK; + break; + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_NEXT_REQ): + /* GetNextRequest PDU */ + snmp_inc_snmpingetnexts(); + derr = ERR_OK; + break; + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP): + /* GetResponse PDU */ + snmp_inc_snmpingetresponses(); + derr = ERR_ARG; + break; + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_SET_REQ): + /* SetRequest PDU */ + snmp_inc_snmpinsetrequests(); + derr = ERR_OK; + break; + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP): + /* Trap PDU */ + snmp_inc_snmpintraps(); + derr = ERR_ARG; + break; + default: + snmp_inc_snmpinasnparseerrs(); + derr = ERR_ARG; + break; + } + if (derr != ERR_OK) + { + /* unsupported input PDU for this agent */ + return ERR_ARG; + } + m_stat->rt = type & 0x1F; + if (type & SNMP_ASN1_CONSTR) + { + ofs += (1 + len_octets); + } + else + { + ofs += (1 + len_octets + len); + } + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) + { + /* can't decode or no integer (request ID) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->rid); + if (derr != ERR_OK) + { + /* can't decode */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + if (type & SNMP_ASN1_CONSTR) + { + ofs += (1 + len_octets); + } + else + { + ofs += (1 + len_octets + len); + } + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) + { + /* can't decode or no integer (error-status) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + /* usually noError (0) for incoming messages but log errors + for mib-2 completeness and for debug purposes */ + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_status); + if (derr != ERR_OK) + { + /* can't decode */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + switch (m_stat->error_status) + { + case SNMP_ES_TOOBIG: + snmp_inc_snmpintoobigs(); + break; + case SNMP_ES_NOSUCHNAME: + snmp_inc_snmpinnosuchnames(); + break; + case SNMP_ES_BADVALUE: + snmp_inc_snmpinbadvalues(); + break; + case SNMP_ES_READONLY: + snmp_inc_snmpinreadonlys(); + break; + case SNMP_ES_GENERROR: + snmp_inc_snmpingenerrs(); + break; + } + if (type & SNMP_ASN1_CONSTR) + { + ofs += (1 + len_octets); + } + else + { + ofs += (1 + len_octets + len); + } + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) + { + /* can't decode or no integer (error-index) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + /* skip 'error-index', usually 0 for incoming requests */ + if (type & SNMP_ASN1_CONSTR) + { + ofs += (1 + len_octets); + } + else + { + ofs += (1 + len_octets + len); + } + *ofs_ret = ofs; + return ERR_OK; +} + +static err_t +snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat) +{ + err_t derr; + u16_t len, vb_len; + u8_t len_octets; + u8_t type; + + /* variable binding list */ + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &vb_len); + if ((derr != ERR_OK) || + (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) + { + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + ofs += (1 + len_octets); + + /* start with empty list */ + m_stat->invb.count = 0; + m_stat->invb.head = NULL; + m_stat->invb.tail = NULL; + + while (vb_len > 0) + { + struct snmp_obj_id oid, oid_value; + struct snmp_varbind *vb; + + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || + (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) + { + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + ofs += (1 + len_octets); + vb_len -= (1 + len_octets); + + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID))) + { + /* can't decode object name length */ + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid); + if (derr != ERR_OK) + { + /* can't decode object name */ + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + ofs += (1 + len_octets + len); + vb_len -= (1 + len_octets + len); + + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if (derr != ERR_OK) + { + /* can't decode object value length */ + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + + switch (type) + { + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG): + vb = snmp_varbind_alloc(&oid, type, sizeof(s32_t)); + if (vb != NULL) + { + s32_t *vptr = vb->value; + + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, vptr); + snmp_varbind_tail_add(&m_stat->invb, vb); + } + else + { + derr = ERR_ARG; + } + break; + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS): + vb = snmp_varbind_alloc(&oid, type, sizeof(u32_t)); + if (vb != NULL) + { + u32_t *vptr = vb->value; + + derr = snmp_asn1_dec_u32t(p, ofs + 1 + len_octets, len, vptr); + snmp_varbind_tail_add(&m_stat->invb, vb); + } + else + { + derr = ERR_ARG; + } + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE): + vb = snmp_varbind_alloc(&oid, type, len); + if (vb != NULL) + { + derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, vb->value); + snmp_varbind_tail_add(&m_stat->invb, vb); + } + else + { + derr = ERR_ARG; + } + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL): + vb = snmp_varbind_alloc(&oid, type, 0); + if (vb != NULL) + { + snmp_varbind_tail_add(&m_stat->invb, vb); + derr = ERR_OK; + } + else + { + derr = ERR_ARG; + } + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID): + derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid_value); + if (derr == ERR_OK) + { + vb = snmp_varbind_alloc(&oid, type, oid_value.len * sizeof(s32_t)); + if (vb != NULL) + { + u8_t i = oid_value.len; + s32_t *vptr = vb->value; + + while(i > 0) + { + i--; + vptr[i] = oid_value.id[i]; + } + snmp_varbind_tail_add(&m_stat->invb, vb); + derr = ERR_OK; + } + else + { + derr = ERR_ARG; + } + } + break; + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR): + if (len == 4) + { + /* must be exactly 4 octets! */ + vb = snmp_varbind_alloc(&oid, type, 4); + if (vb != NULL) + { + derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, vb->value); + snmp_varbind_tail_add(&m_stat->invb, vb); + } + else + { + derr = ERR_ARG; + } + } + else + { + derr = ERR_ARG; + } + break; + default: + derr = ERR_ARG; + break; + } + if (derr != ERR_OK) + { + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + ofs += (1 + len_octets + len); + vb_len -= (1 + len_octets + len); + } + + if (m_stat->rt == SNMP_ASN1_PDU_SET_REQ) + { + snmp_add_snmpintotalsetvars(m_stat->invb.count); + } + else + { + snmp_add_snmpintotalreqvars(m_stat->invb.count); + } + + *ofs_ret = ofs; + return ERR_OK; +} + +static struct snmp_varbind* +snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len) +{ + struct snmp_varbind *vb; + + vb = (struct snmp_varbind *)mem_malloc(sizeof(struct snmp_varbind)); + if (vb != NULL) + { + u8_t i; + + vb->next = NULL; + vb->prev = NULL; + i = oid->len; + vb->ident_len = i; + /* allocate array of s32_t for our object identifier */ + vb->ident = (s32_t*)mem_malloc(sizeof(s32_t) * i); + if (vb->ident == NULL) + { + mem_free(vb); + return NULL; + } + while(i > 0) + { + i--; + vb->ident[i] = oid->id[i]; + } + vb->value_type = type; + vb->value_len = len; + if (len > 0) + { + /* allocate raw bytes for our object value */ + vb->value = mem_malloc(len); + if (vb->value == NULL) + { + mem_free(vb->ident); + mem_free(vb); + return NULL; + } + } + else + { + /* ASN1_NUL type, or zero length ASN1_OC_STR */ + vb->value = NULL; + } + } + return vb; +} + +static void +snmp_varbind_free(struct snmp_varbind *vb) +{ + if (vb->value != NULL ) + { + mem_free(vb->value); + } + if (vb->ident != NULL ) + { + mem_free(vb->ident); + } + mem_free(vb); +} + +static void +snmp_varbind_list_free(struct snmp_varbind_root *root) +{ + struct snmp_varbind *vb; + + vb = root->tail; + while ( vb != NULL ) + { + snmp_varbind_free(vb); + vb = vb->prev; + } + root->count = 0; +} + +static void +snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb) +{ + if (root->count == 0) + { + /* add first varbind to list */ + root->head = vb; + root->tail = vb; + } + else + { + /* add nth varbind to list tail */ + root->tail->next = vb; + vb->prev = root->tail; + root->tail = vb; + } + root->count += 1; +} + +static struct snmp_varbind* +snmp_varbind_tail_remove(struct snmp_varbind_root *root) +{ + struct snmp_varbind* vb; + + if (root->count > 0) + { + /* remove tail varbind */ + vb = root->tail; + root->tail = vb->prev; + vb->prev->next = NULL; + root->count -= 1; + } + else + { + /* nothing to remove */ + vb = NULL; + } + return vb; +} + +#endif /* LWIP_SNMP */ \ No newline at end of file diff --git a/src/core/snmp/msg_out.c b/src/core/snmp/msg_out.c new file mode 100644 index 00000000..9368080e --- /dev/null +++ b/src/core/snmp/msg_out.c @@ -0,0 +1,622 @@ +/** + * @file + * [EXPIRIMENTAL] SNMP output message processing (RFC1157). + * + * Output responses and traps are build in two passes: + * + * Pass 0: iterate over the output message backwards to determine encoding lengths + * Pass 1: the actual forward encoding of internal form into ASN1 + * + * The single-pass encoding method described by Comer & Stevens + * requires extra buffer space and copying for reversal of the packet. + * The buffer requirement can be prohibitively large for big payloads + * (>= 484) therefore we use the two encoding passes. + */ + +/* + * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Christiaan Simons + */ + +#include "arch/cc.h" +#include "lwip/opt.h" +#include "lwip/udp.h" +#include "lwip/netif.h" + +#include "lwip/snmp.h" +#include "lwip/snmp_asn1.h" +#include "lwip/snmp_msg.h" + +#if LWIP_SNMP + +/** + * TRAP message structure + * @todo turn this into an arg to snmp_create_trap ? + */ +struct snmp_msg_trap trap_msg; + +static u16_t snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len); +static u16_t snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len); +static u16_t snmp_varbind_list_sum(struct snmp_varbind_root *root); + +static u16_t snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p); +static u16_t snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p); +static u16_t snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs); + + + +/** + * Sends a 'getresponse' message to the request originator. + * + * @param m_stat points to the current message request state source + * @return ERR_OK when success, ERR_MEM if we're out of memory + * + * @note the caller is responsible for filling in outvb in the m_stat + * @todo caller must provide error-status and index ... + */ +err_t +snmp_send_response(struct snmp_msg_pstat *m_stat) +{ + struct snmp_varbind_root emptyvb = {NULL, NULL, 0, 0, 0}; + struct pbuf *p; + u16_t tot_len; + err_t err; + + m_stat->error_status = SNMP_ES_NOERROR; + m_stat->error_index = 0; + + /* pass 0, calculate length fields */ + tot_len = snmp_varbind_list_sum(&m_stat->outvb); + tot_len = snmp_resp_header_sum(m_stat, tot_len); + + /* try allocating pbuf(s) for complete response */ + p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL); + if (p == NULL) + { + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() tooBig\n")); + + /* can't construct reply, return error-status tooBig */ + m_stat->error_status = SNMP_ES_TOOBIG; + m_stat->error_index = 0; + /* pass 0, recalculate lengths, for empty varbind-list */ + tot_len = snmp_varbind_list_sum(&emptyvb); + tot_len = snmp_resp_header_sum(m_stat, tot_len); + /* retry allocation once for header and empty varbind-list */ + p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL); + } + if (p != NULL) + { + /* first pbuf alloc try or retry alloc success */ + u16_t ofs; + + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() p != NULL\n")); + + /* pass 1, size error, encode packet ino the pbuf(s) */ + ofs = snmp_resp_header_enc(m_stat, p); + if (m_stat->error_status == SNMP_ES_TOOBIG) + { + snmp_varbind_list_enc(&emptyvb, p, ofs); + } + else + { + snmp_varbind_list_enc(&m_stat->outvb, p, ofs); + } + + switch (m_stat->error_status) + { + case SNMP_ES_TOOBIG: + snmp_inc_snmpouttoobigs(); + break; + case SNMP_ES_NOSUCHNAME: + snmp_inc_snmpoutnosuchnames(); + break; + case SNMP_ES_BADVALUE: + snmp_inc_snmpoutbadvalues(); + break; + case SNMP_ES_GENERROR: + snmp_inc_snmpoutgenerrs(); + break; + } + snmp_inc_snmpoutgetresponses(); + snmp_inc_snmpoutpkts(); + + /** @todo do we need separate rx and tx pcbs for threaded case? */ + /** connect to the originating source */ + udp_connect(m_stat->pcb, &m_stat->sip, m_stat->sp); + err = udp_send(m_stat->pcb, p); + if (err == ERR_MEM) + { + /** @todo release some memory, retry and return tooBig? tooMuchHassle? */ + err = ERR_MEM; + } + else + { + err = ERR_OK; + } + /** disassociate remote address and port with this pcb */ + udp_disconnect(m_stat->pcb); + + pbuf_free(p); + return err; + } + else + { + /* first pbuf alloc try or retry alloc failed + very low on memory, couldn't return tooBig */ + return ERR_MEM; + } +} + + +/** + * Sends an generic or enterprise specific trap message. + * + * @param dst points to the trap destination IPv4 address + * @param generic_trap is the trap code + * @param specific_trap used for enterprise traps when generic_trap == 6 + * @return ERR_OK when success, ERR_MEM if we're out of memory + * + * @note the caller is responsible for filling in outvb in the trap_msg + * @note the use of the enterpise identifier field + * is per RFC1215. + * Use .iso.org.dod.internet.mgmt.mib-2.snmp for generic traps + * and .iso.org.dod.internet.private.enterprises.yourenterprise + * (sysObjectID) for specific traps. + */ +err_t +snmp_send_trap(struct ip_addr *dst, s8_t generic_trap, s32_t specific_trap) +{ + struct netif *dst_if; + struct pbuf *p; + u16_t tot_len; + + /* network order trap destination */ + trap_msg.dip.addr = htons(dst->addr); + /* lookup current source address for this dst */ + dst_if = ip_route(dst); + trap_msg.sip_raw[0] = dst_if->ip_addr.addr >> 24; + trap_msg.sip_raw[1] = dst_if->ip_addr.addr >> 16; + trap_msg.sip_raw[2] = dst_if->ip_addr.addr >> 8; + trap_msg.sip_raw[3] = dst_if->ip_addr.addr; + trap_msg.gen_trap = generic_trap; + trap_msg.spc_trap = specific_trap; + if (generic_trap == 6) + { + /* enterprise-Specific trap */ + snmp_get_sysobjid(&trap_msg.enterprise); + } + else + { + /* generic (MIB-II) trap */ + snmp_get_snmpgrpid(&trap_msg.enterprise); + } + snmp_get_sysuptime(&trap_msg.ts); + + /* pass 0, calculate length fields */ + tot_len = snmp_varbind_list_sum(&trap_msg.outvb); + tot_len = snmp_trap_header_sum(&trap_msg, tot_len); + + /* allocate pbuf(s) */ + p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL); + if (p != NULL) + { + u16_t ofs; + + /* pass 1, encode packet ino the pbuf(s) */ + ofs = snmp_trap_header_enc(&trap_msg, p); + snmp_varbind_list_enc(&trap_msg.outvb, p, ofs); + + snmp_inc_snmpouttraps(); + snmp_inc_snmpoutpkts(); + + /** connect to the TRAP destination */ + udp_connect(trap_msg.pcb, &trap_msg.dip, SNMP_TRAP_PORT); + udp_send(trap_msg.pcb, p); + /** disassociate remote address and port with this pcb */ + udp_disconnect(trap_msg.pcb); + + pbuf_free(p); + return ERR_OK; + } + else + { + return ERR_MEM; + } +} + +/** + * Sums response header field lengths from tail to head and + * returns resp_header_lengths for second encoding pass. + * + * @param vb_len varbind-list length + * @param rhl points to returned header lengths + * @return the required lenght for encoding the response header + */ +static u16_t +snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len) +{ + u16_t tot_len; + struct snmp_resp_header_lengths *rhl; + + rhl = &m_stat->rhl; + tot_len = vb_len; + snmp_asn1_enc_s32t_cnt(m_stat->error_index, &rhl->erridxlen); + snmp_asn1_enc_length_cnt(rhl->erridxlen, &rhl->erridxlenlen); + tot_len += 1 + rhl->erridxlenlen + rhl->erridxlen; + + snmp_asn1_enc_s32t_cnt(m_stat->error_status, &rhl->errstatlen); + snmp_asn1_enc_length_cnt(rhl->errstatlen, &rhl->errstatlenlen); + tot_len += 1 + rhl->errstatlenlen + rhl->errstatlen; + + snmp_asn1_enc_s32t_cnt(m_stat->rid, &rhl->ridlen); + snmp_asn1_enc_length_cnt(rhl->ridlen, &rhl->ridlenlen); + tot_len += 1 + rhl->ridlenlen + rhl->ridlen; + + rhl->pdulen = tot_len; + snmp_asn1_enc_length_cnt(rhl->pdulen, &rhl->pdulenlen); + tot_len += 1 + rhl->pdulenlen; + + rhl->comlen = m_stat->com_strlen; + snmp_asn1_enc_length_cnt(rhl->comlen, &rhl->comlenlen); + tot_len += 1 + rhl->comlenlen + rhl->comlen; + + snmp_asn1_enc_s32t_cnt(snmp_version, &rhl->verlen); + snmp_asn1_enc_length_cnt(rhl->verlen, &rhl->verlenlen); + tot_len += 1 + rhl->verlen + rhl->verlenlen; + + rhl->seqlen = tot_len; + snmp_asn1_enc_length_cnt(rhl->seqlen, &rhl->seqlenlen); + tot_len += 1 + rhl->seqlenlen; + + return tot_len; +} + +/** + * Sums trap header field lengths from tail to head and + * returns trap_header_lengths for second encoding pass. + * + * @param vb_len varbind-list length + * @param thl points to returned header lengths + * @return the required lenght for encoding the trap header + */ +static u16_t +snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len) +{ + u16_t tot_len; + struct snmp_trap_header_lengths *thl; + + thl = &m_trap->thl; + tot_len = vb_len; + + snmp_asn1_enc_u32t_cnt(m_trap->ts, &thl->tslen); + snmp_asn1_enc_length_cnt(thl->tslen, &thl->tslenlen); + tot_len += 1 + thl->tslen + thl->tslenlen; + + snmp_asn1_enc_s32t_cnt(m_trap->spc_trap, &thl->strplen); + snmp_asn1_enc_length_cnt(thl->strplen, &thl->strplenlen); + tot_len += 1 + thl->strplen + thl->strplenlen; + + snmp_asn1_enc_s32t_cnt(m_trap->gen_trap, &thl->gtrplen); + snmp_asn1_enc_length_cnt(thl->gtrplen, &thl->gtrplenlen); + tot_len += 1 + thl->gtrplen + thl->gtrplenlen; + + thl->aaddrlen = 4; + snmp_asn1_enc_length_cnt(thl->aaddrlen, &thl->aaddrlenlen); + tot_len += 1 + thl->aaddrlen + thl->aaddrlenlen; + + snmp_asn1_enc_oid_cnt(m_trap->enterprise->len, &m_trap->enterprise->id[0], &thl->eidlen); + snmp_asn1_enc_length_cnt(thl->eidlen, &thl->eidlenlen); + tot_len += 1 + thl->eidlen + thl->eidlenlen; + + thl->pdulen = tot_len; + snmp_asn1_enc_length_cnt(thl->pdulen, &thl->pdulenlen); + tot_len += 1 + thl->pdulenlen; + + thl->comlen = sizeof(snmp_publiccommunity) - 1; + snmp_asn1_enc_length_cnt(thl->comlen, &thl->comlenlen); + tot_len += 1 + thl->comlenlen + thl->comlen; + + snmp_asn1_enc_s32t_cnt(snmp_version, &thl->verlen); + snmp_asn1_enc_length_cnt(thl->verlen, &thl->verlenlen); + tot_len += 1 + thl->verlen + thl->verlenlen; + + thl->seqlen = tot_len; + snmp_asn1_enc_length_cnt(thl->seqlen, &thl->seqlenlen); + tot_len += 1 + thl->seqlenlen; + + return tot_len; +} + +/** + * Sums varbind lengths from tail to head and + * annotates lengths in varbind for second encoding pass. + * + * @param root points to the root of the variable binding list + * @return the required lenght for encoding the variable bindings + */ +static u16_t +snmp_varbind_list_sum(struct snmp_varbind_root *root) +{ + struct snmp_varbind *vb; + u32_t *uint_ptr; + s32_t *sint_ptr; + u16_t tot_len; + + tot_len = 0; + vb = root->tail; + while ( vb != NULL ) + { + /* encoded value lenght depends on type */ + switch (vb->value_type) + { + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG): + sint_ptr = vb->value; + snmp_asn1_enc_s32t_cnt(*sint_ptr, &vb->vlen); + break; + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS): + uint_ptr = vb->value; + snmp_asn1_enc_u32t_cnt(*uint_ptr, &vb->vlen); + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR): + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE): + vb->vlen = vb->value_len; + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID): + sint_ptr = vb->value; + snmp_asn1_enc_oid_cnt(vb->value_len / sizeof(s32_t), sint_ptr, &vb->vlen); + break; + default: + /* unsupported type */ + vb->vlen = 0; + break; + }; + /* encoding length of value length field */ + snmp_asn1_enc_length_cnt(vb->vlen, &vb->vlenlen); + snmp_asn1_enc_oid_cnt(vb->ident_len, vb->ident, &vb->olen); + snmp_asn1_enc_length_cnt(vb->olen, &vb->olenlen); + + vb->seqlen = 1 + vb->vlenlen + vb->vlen; + vb->seqlen += 1 + vb->olenlen + vb->olen; + snmp_asn1_enc_length_cnt(vb->seqlen, &vb->seqlenlen); + + /* varbind seq */ + tot_len += 1 + vb->seqlenlen + vb->seqlen; + + vb = vb->prev; + } + + /* varbind-list seq */ + root->seqlen = tot_len; + snmp_asn1_enc_length_cnt(root->seqlen, &root->seqlenlen); + tot_len += 1 + root->seqlenlen; + + return tot_len; +} + +/** + * Encodes response header from head to tail. + */ +static u16_t +snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p) +{ + u16_t ofs; + + ofs = 0; + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_stat->rhl.seqlen); + ofs += m_stat->rhl.seqlenlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_stat->rhl.verlen); + ofs += m_stat->rhl.verlenlen; + snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.verlen, snmp_version); + ofs += m_stat->rhl.verlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_stat->rhl.comlen); + ofs += m_stat->rhl.comlenlen; + snmp_asn1_enc_raw(p, ofs, m_stat->rhl.comlen, m_stat->community); + ofs += m_stat->rhl.comlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_stat->rhl.pdulen); + ofs += m_stat->rhl.pdulenlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_stat->rhl.ridlen); + ofs += m_stat->rhl.ridlenlen; + snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.ridlen, m_stat->rid); + ofs += m_stat->rhl.ridlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_stat->rhl.errstatlen); + ofs += m_stat->rhl.errstatlenlen; + snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.errstatlen, m_stat->error_status); + ofs += m_stat->rhl.errstatlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_stat->rhl.erridxlen); + ofs += m_stat->rhl.erridxlenlen; + snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.erridxlen, m_stat->error_index); + ofs += m_stat->rhl.erridxlen; + + return ofs; +} + +/** + * Encodes trap header from head to tail. + */ +static u16_t +snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p) +{ + u16_t ofs; + + ofs = 0; + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.seqlen); + ofs += m_trap->thl.seqlenlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.verlen); + ofs += m_trap->thl.verlenlen; + snmp_asn1_enc_s32t(p, ofs, m_trap->thl.verlen, snmp_version); + ofs += m_trap->thl.verlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.comlen); + ofs += m_trap->thl.comlenlen; + snmp_asn1_enc_raw(p, ofs, m_trap->thl.comlen, (u8_t *)&snmp_publiccommunity[0]); + ofs += m_trap->thl.comlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.pdulen); + ofs += m_trap->thl.pdulenlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.eidlen); + ofs += m_trap->thl.eidlenlen; + snmp_asn1_enc_oid(p, ofs, m_trap->enterprise->len, &m_trap->enterprise->id[0]); + ofs += m_trap->thl.eidlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.aaddrlen); + ofs += m_trap->thl.aaddrlenlen; + snmp_asn1_enc_raw(p, ofs, m_trap->thl.aaddrlen, &m_trap->sip_raw[0]); + ofs += m_trap->thl.aaddrlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.gtrplen); + ofs += m_trap->thl.gtrplenlen; + snmp_asn1_enc_u32t(p, ofs, m_trap->thl.gtrplen, m_trap->gen_trap); + ofs += m_trap->thl.gtrplen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.strplen); + ofs += m_trap->thl.strplenlen; + snmp_asn1_enc_u32t(p, ofs, m_trap->thl.strplen, m_trap->spc_trap); + ofs += m_trap->thl.strplen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, m_trap->thl.tslen); + ofs += m_trap->thl.tslenlen; + snmp_asn1_enc_u32t(p, ofs, m_trap->thl.tslen, m_trap->ts); + ofs += m_trap->thl.tslen; + + return ofs; +} + +/** + * Encodes varbind list from head to tail. + */ +static u16_t +snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs) +{ + struct snmp_varbind *vb; + s32_t *sint_ptr; + u32_t *uint_ptr; + u8_t *raw_ptr; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, root->seqlen); + ofs += root->seqlenlen; + + vb = root->head; + while ( vb != NULL ) + { + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, vb->seqlen); + ofs += vb->seqlenlen; + + snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID)); + ofs += 1; + snmp_asn1_enc_length(p, ofs, vb->olen); + ofs += vb->olenlen; + snmp_asn1_enc_oid(p, ofs, vb->ident_len, &vb->ident[0]); + ofs += vb->olen; + + snmp_asn1_enc_type(p, ofs, vb->value_type); + ofs += 1; + snmp_asn1_enc_length(p, ofs, vb->vlen); + ofs += vb->vlenlen; + + switch (vb->value_type) + { + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG): + sint_ptr = vb->value; + snmp_asn1_enc_s32t(p, ofs, vb->vlen, *sint_ptr); + break; + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS): + uint_ptr = vb->value; + snmp_asn1_enc_u32t(p, ofs, vb->vlen, *uint_ptr); + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE): + raw_ptr = vb->value; + snmp_asn1_enc_raw(p, ofs, vb->vlen, raw_ptr); + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL): + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID): + sint_ptr = vb->value; + snmp_asn1_enc_oid(p, ofs, vb->value_len / sizeof(s32_t), sint_ptr); + break; + default: + /* unsupported type */ + break; + }; + ofs += vb->vlen; + vb = vb->next; + } + return ofs; +} + +#endif /* LWIP_SNMP */ \ No newline at end of file diff --git a/src/include/lwip/snmp_asn1.h b/src/include/lwip/snmp_asn1.h new file mode 100644 index 00000000..56c71bec --- /dev/null +++ b/src/include/lwip/snmp_asn1.h @@ -0,0 +1,90 @@ +/** + * @file + * [EXPIRIMENTAL] Abstract Syntax Notation One (ISO 8824, 8825) codec. + */ + +/* + * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Christiaan Simons + */ + +#ifndef __LWIP_SNMP_ASN1_H__ +#define __LWIP_SNMP_ASN1_H__ + +#include "lwip/opt.h" +#include "arch/cc.h" +#include "lwip/err.h" +#include "lwip/pbuf.h" +#include "lwip/snmp.h" + +#define SNMP_ASN1_UNIV (!0x80 | !0x40) +#define SNMP_ASN1_APPLIC (!0x80 | 0x40) +#define SNMP_ASN1_CONTXT ( 0x80 | !0x40) + +#define SNMP_ASN1_CONSTR (0x20) +#define SNMP_ASN1_PRIMIT (!0x20) + +/* universal tags */ +#define SNMP_ASN1_INTEG 2 +#define SNMP_ASN1_OC_STR 4 +#define SNMP_ASN1_NUL 5 +#define SNMP_ASN1_OBJ_ID 6 +#define SNMP_ASN1_SEQ 16 + +/* application specific (SNMP) tags */ +#define SNMP_ASN1_IPADDR 0 /* octet string size(4) */ +#define SNMP_ASN1_COUNTER 1 /* u32_t */ +#define SNMP_ASN1_GAUGE 2 /* u32_t */ +#define SNMP_ASN1_TIMETICKS 3 /* u32_t */ +#define SNMP_ASN1_OPAQUE 4 /* octet string */ + +/* context specific (SNMP) tags */ +#define SNMP_ASN1_PDU_GET_REQ 0 +#define SNMP_ASN1_PDU_GET_NEXT_REQ 1 +#define SNMP_ASN1_PDU_GET_RESP 2 +#define SNMP_ASN1_PDU_SET_REQ 3 +#define SNMP_ASN1_PDU_TRAP 4 + +err_t snmp_asn1_dec_type(struct pbuf *p, u16_t ofs, u8_t *type); +err_t snmp_asn1_dec_length(struct pbuf *p, u16_t ofs, u8_t *octets_used, u16_t *length); +err_t snmp_asn1_dec_u32t(struct pbuf *p, u16_t ofs, u16_t len, u32_t *value); +err_t snmp_asn1_dec_s32t(struct pbuf *p, u16_t ofs, u16_t len, s32_t *value); +err_t snmp_asn1_dec_oid(struct pbuf *p, u16_t ofs, u16_t len, struct snmp_obj_id *oid); +err_t snmp_asn1_dec_raw(struct pbuf *p, u16_t ofs, u16_t len, u16_t raw_len, u8_t *raw); + +void snmp_asn1_enc_length_cnt(u16_t length, u8_t *octets_needed); +void snmp_asn1_enc_u32t_cnt(u32_t value, u16_t *octets_needed); +void snmp_asn1_enc_s32t_cnt(s32_t value, u16_t *octets_needed); +void snmp_asn1_enc_oid_cnt(u8_t ident_len, s32_t *ident, u16_t *octets_needed); +err_t snmp_asn1_enc_type(struct pbuf *p, u16_t ofs, u8_t type); +err_t snmp_asn1_enc_length(struct pbuf *p, u16_t ofs, u16_t length); +err_t snmp_asn1_enc_u32t(struct pbuf *p, u16_t ofs, u8_t octets_needed, u32_t value); +err_t snmp_asn1_enc_s32t(struct pbuf *p, u16_t ofs, u8_t octets_needed, s32_t value); +err_t snmp_asn1_enc_oid(struct pbuf *p, u16_t ofs, u8_t ident_len, s32_t *ident); +err_t snmp_asn1_enc_raw(struct pbuf *p, u16_t ofs, u8_t raw_len, u8_t *raw); + +#endif diff --git a/src/include/lwip/snmp_msg.h b/src/include/lwip/snmp_msg.h new file mode 100644 index 00000000..005d0a05 --- /dev/null +++ b/src/include/lwip/snmp_msg.h @@ -0,0 +1,267 @@ +/** + * @file + * [EXPIRIMENTAL] SNMP Agent message handling structures. + */ + +/* + * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Christiaan Simons + */ + +#ifndef __LWIP_SNMP_MSG_H__ +#define __LWIP_SNMP_MSG_H__ + +#include "lwip/opt.h" +#include "arch/cc.h" +#include "lwip/snmp.h" + +#if SNMP_PRIVATE_MIB +#include "private_mib.h" +#endif + +#define SNMP_IN_PORT 161 +#define SNMP_TRAP_PORT 162 + +#define SNMP_ES_NOERROR 0 +#define SNMP_ES_TOOBIG 1 +#define SNMP_ES_NOSUCHNAME 2 +#define SNMP_ES_BADVALUE 3 +#define SNMP_ES_READONLY 4 +#define SNMP_ES_GENERROR 5 + +struct snmp_varbind +{ + /* next pointer, NULL for last in list */ + struct snmp_varbind *next; + /* previous pointer, NULL for first in list */ + struct snmp_varbind *prev; + + /* object identifier length (in s32_t) */ + u8_t ident_len; + /* object identifier array */ + s32_t *ident; + + /* object value ASN1 type */ + u8_t value_type; + /* object value length (in u8_t) */ + u8_t value_len; + /* object value */ + void *value; + + /* encoding varbind seq length length */ + u8_t seqlenlen; + /* encoding object identifier length length */ + u8_t olenlen; + /* encoding object value length length */ + u8_t vlenlen; + /* encoding varbind seq length */ + u16_t seqlen; + /* encoding object identifier length */ + u16_t olen; + /* encoding object value length */ + u16_t vlen; +}; + +struct snmp_varbind_root +{ + struct snmp_varbind *head; + struct snmp_varbind *tail; + /* number of variable bindings in list */ + u8_t count; + /* encoding varbind-list seq length length */ + u8_t seqlenlen; + /* encoding varbind-list seq length */ + u16_t seqlen; +}; + +/** output response message header length fields */ +struct snmp_resp_header_lengths +{ + /* encoding error-index length length */ + u8_t erridxlenlen; + /* encoding error-status length length */ + u8_t errstatlenlen; + /* encoding request id length length */ + u8_t ridlenlen; + /* encoding pdu length length */ + u8_t pdulenlen; + /* encoding community length length */ + u8_t comlenlen; + /* encoding version length length */ + u8_t verlenlen; + /* encoding sequence length length */ + u8_t seqlenlen; + + /* encoding error-index length */ + u16_t erridxlen; + /* encoding error-status length */ + u16_t errstatlen; + /* encoding request id length */ + u16_t ridlen; + /* encoding pdu length */ + u16_t pdulen; + /* encoding community length */ + u16_t comlen; + /* encoding version length */ + u16_t verlen; + /* encoding sequence length */ + u16_t seqlen; +}; + +/** output response message header length fields */ +struct snmp_trap_header_lengths +{ + /* encoding timestamp length length */ + u8_t tslenlen; + /* encoding specific-trap length length */ + u8_t strplenlen; + /* encoding generic-trap length length */ + u8_t gtrplenlen; + /* encoding agent-addr length length */ + u8_t aaddrlenlen; + /* encoding enterprise-id length length */ + u8_t eidlenlen; + /* encoding pdu length length */ + u8_t pdulenlen; + /* encoding community length length */ + u8_t comlenlen; + /* encoding version length length */ + u8_t verlenlen; + /* encoding sequence length length */ + u8_t seqlenlen; + + /* encoding timestamp length */ + u16_t tslen; + /* encoding specific-trap length */ + u16_t strplen; + /* encoding generic-trap length */ + u16_t gtrplen; + /* encoding agent-addr length */ + u16_t aaddrlen; + /* encoding enterprise-id length */ + u16_t eidlen; + /* encoding pdu length */ + u16_t pdulen; + /* encoding community length */ + u16_t comlen; + /* encoding version length */ + u16_t verlen; + /* encoding sequence length */ + u16_t seqlen; +}; + +/* can accept new SNMP message */ +#define SNMP_MSG_EMPTY 0 +/* decode SNMP variable binding */ +#define SNMP_MSG_DEMUX 1 +/* perform SNMP operation on varbind for in-memory case */ +#define SNMP_MSG_INTERNAL 2 +/* perform SNMP operation on private varbind external case */ +#define SNMP_MSG_EXTERNAL 3 + + +#define SNMP_COMMUNITY_STR_LEN 64 +struct snmp_msg_pstat +{ +#if 0 + struct snmp_msg_pstat *next; +#endif + /* lwIP local port (161) binding */ + struct udp_pcb *pcb; + /* source IP address */ + struct ip_addr sip; + /* source UDP port */ + u16_t sp; + /* request type */ + u8_t rt; + /* request ID */ + s32_t rid; + /* error status */ + s32_t error_status; + /* error index */ + s32_t error_index; + /* community name (zero terminated) */ + u8_t community[SNMP_COMMUNITY_STR_LEN + 1]; + /* community string length (exclusive zero term) */ + u8_t com_strlen; + /* one out of MSG_EMPTY, MSG_DEMUX, MSG_MGMT, MSG_PRIVATE */ + u8_t state; + /* list of variable bindings from input */ + struct snmp_varbind_root invb; + /* list of variable bindings to output */ + struct snmp_varbind_root outvb; + /* output response lengths used in ASN encoding */ + struct snmp_resp_header_lengths rhl; +#if SNMP_PRIVATE_MIB + struct private_state ps; +#endif +}; + +struct snmp_msg_trap +{ +#if 0 + struct snmp_msg_trap *next; +#endif + /* lwIP local port (161) binding */ + struct udp_pcb *pcb; + /* destination IP address in network order */ + struct ip_addr dip; + + /* source enterprise ID (sysObjectID) */ + struct snmp_obj_id *enterprise; + /* source IP address, raw network order format */ + u8_t sip_raw[4]; + /* generic trap code */ + u32_t gen_trap; + /* specific trap code */ + u32_t spc_trap; + /* timestamp */ + u32_t ts; + /* list of variable bindings to output */ + struct snmp_varbind_root outvb; + /* output trap lengths used in ASN encoding */ + struct snmp_trap_header_lengths thl; +#if SNMP_PRIVATE_MIB + /** @todo is this really needed? */ + struct private_state ps; +#endif +}; + +/** Agent Version constant, 0 = v1 oddity */ +extern const s32_t snmp_version; +/** Agent default "public" community string */ +extern const char snmp_publiccommunity[7]; + +extern struct snmp_msg_trap trap_msg; + +/** Agent setup, start listening to port 161. */ +void snmp_init(void); + +err_t snmp_send_response(struct snmp_msg_pstat *m_stat); +err_t snmp_send_trap(struct ip_addr *dst, s8_t generic_trap, s32_t specific_trap); + +#endif